The irradiation tests of Silicon pad sensors for the new ALICE FoCal detector at the LHC

It is important to check the radiation tolerance of silicon pad sensors for the new ALICE FoCal detector at the LHC before mass production begins. An irradiation test of the main sensors and small single-cell sensors was carried out at the RIKEN RANS facility in Wako city, Japan, in July, 2023. The most-irradiated single-cell sensor obtained approximately 5 x 1013 1 MeV neq / cm2. The measured leakage current of the sensor increased from 2 nA to 89 mu A after irradiation with neutrons and decreased to 41 mu A by a long-term annealing effect at room temperature with a bias voltage of 500 V. The temperature dependence of the I-V characteristics of the irradiated sensors was measured using a handmade temperature-controllable black box with Peltier devices as well.